Pahi42 cockpit mounting

[Ken Blandford]

I am in the process of building the Pahi42 cockpit.

The plans call for 2x1 hardwood rails attached to the bottom inside edges of beams 3 and 4 with matching rails on the fore and aft sides of the cockpit. These rails would obviously need to be laminated to enable the hardwood 2x1 to follow the bottom curve of the beams, The cockpit is the lowered from the top to rest on these rails.

My problem is that there is not enough headroom between the tops of the beams and my shed roof to be able to raise the cockpit high enough to enable it to be be lowered down between the beams onto the support rails.

My question is has anyone mounted the cockpit from it`s ends?

My thought is to attach short fore and aft beams behind the seat backrests at each end, at the same vertical position as the rails shown on the plans. These would then be supported on hardwood blocks attached to the bottom inside edges of beams 3&4.

These short beams could be fitted temporarily, and then removed to allow the cockpit to be raised from below and supported high enough to be able to refit these  beams and then lower the cockpit down onto the support blocks.

Has anyone done something similar?

If this is possible would the cockpit need extra structual modification, considering the outboard mounting brackets are fitted to the bottom of the cockpit?

Any advice concerning this would be greatly appriciated.

Ken.

[Robert]

Regarding the rails as given in the plans, I’m not sure it’s worth following the curve of the beams. It’s difficult to match that curve exactly on the cockpit box. It would be easier to use straight rails and just add shims on the beams to support the rails.

As designed, the cockpit box is evenly supported for approximately 9 feet along each side. Your idea concentrates loads at two points on each end. This would have to be very well engineered. The box itself would have to be significantly beefed up. It’s not just about the box itself… it’s also about how the thrust of the engines is transmitted to the boat. Failure here would be catastrophic.

The modular nature of the boat means you can build the cockpit separately and mount it to the boat at a later point. You’re going to need a crane to step the mast—that would be a good time to lift in the cockpit and pod.

[Robert]

I suppose it would be possible to fabricate the cockpit box without the rails. Then push it up from below until the top is a little higher than the beams. Then attach the rails.

[Ken Blandford]

Thanks for your input Robert, I really appreciate you taking the time and making the effort to respond.

I had not considered using straight rails with support blocks, so I will take a closer look at that possibility. Unfortunately finding quality straight hardwood at a reasonable price is very difficult here at the moment.

I have considered your suggestion of raising the cockpit up high enough to then fit the side rails, and that seems the most likely way I will go.

Thanks again Robert,

Regards Ken.

[Andy Best-Dunkley]

Hi - this is how I made the new cockpit for our Pahi 42. It is laminated with glass cloth on all sides inside and out, and all the joints are filleted and triple-taped. Our two motors hand underneath as well. As you can see, everything hangs from the "beams" built into the backrest design. So far no problems.

[Lovako]

It would work as Robert sugested.

I built a bigger box to fit between beam 2 and 3 and a smaller one between beam 3 and 4 for my stearing setup.

What I did was to lower the boxes from the top till it just cleared the top beam, then I drew the beam curve on the front and rear of the box wall, pushed it back up a bit and glued and screwed a 20mm thick lip to it.

I did however put extra safety pins (25mm stainless pipe) through the box wall and beam and second box wall.

All for extra safety - it has worked well for 10 years going through some huge storms between South Africa and Madagascar.

I am now in the process of rebuilding them.

Dries from Madagascar

[Lovako]

Here is a pic of how I did it